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Among many shape memory alloys, nickel-titanium (NiTi) alloys are popular due to their superior properties in shape memory effect and superelasticity. They are presently often used in microengineering and medical technology especially in orthopedic and orthodontic implants due to their specific properties. In this study, the electric discharge machine characteristics of NiTi shape memory alloys have been fully investigated by full factorial design. Analysis of mean showed that the material removal rate of NiTi in the electric discharge machine process significantly related to the electrodischarge energy, involving the pulse current and pulse duration. Many electrodischarge craters and recast layers were observed on the electric discharge machine surface of NiTi samples. In addition, there was no significant difference between copper (Cu) and tungsten-copper (W-Cu) electrodes in material removal rate but work stability of W-Cu electrode was longer. On the contrary, quantity of impurity on the surface of the Cu electrode was lower. The specimen's hardness near the outer surface could reach 1200 Hv, which originated from the hardening effect of the recast layer. Here, the microstructure, composition, and hardness of electric discharge machine surfaces are also discussed.

Critical infrastructures are the most important sector in countries because of the essentiality of nation security, public safety, socioeconomic security, and way of life. According to the importance of infrastructures, it is a necessity to analyze the potential risks to do not allow these risks convert into events. The main purpose of this paper is to provide a developed framework with the aim to overcome limitations of the classical approach to build a more secure, safer, and more resilient critical infrastructures in order to develop, implement, control. The proposed framework extends conventional RAMCAP (Risk Analysis and Management for Critical Asset Protection) through introducing new parameters the effects on risk value. According to the complexity of problem and the inherent uncertainty, this research adopts the fuzzy TOPSIS as a fuzzy multi criteria decision making technique to determine the weights of each criterion and the importance of alternatives with respect to criteria. Case analysis is implemented to illustrate the capability and effectiveness of the model for ranking the risk of critical infrastructures. The proposed model demonstrates a significant ISSN 1941-899X 2012 www.macrothink.org/jmr 2 improvement in comparison with conventional RAMCAP. Journal of Management Research

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Pipelines systems are identified to be the safest way of transporting oil and natural gas. One of the most important aspects in developing pipeline systems is determining the potential risks that implementers may encounter. Therefore, risk analysis can determine critical risk items to allocate the limited resources and time. Risk Analysis and Management for Critical Asset Protection (RAMCAP) is one of the best methodologies for assessing the security risks. However, the most challenging problem in this method is uncertainty. Therefore, fuzzy set theory is used to model the uncertainty. Thus, Fuzzy RAMCAP is introduced in order to risk analysis and management for pipeline systems. Finally, a notional example from pipeline systems is provided to demonstrate an application of the proposed methodology.